fix(instances): domain edits start from the persistent definition

Edits that redefine a domain read the wrong XML:
- boot menu/order, vCPU hotplug and QoS read XMLDesc(0), which has no
  secrets, so every such edit, even on a stopped VM, removed the VNC
  password from the definition;
- console, video, CPU, memory and title/description edits read the live
  XML, so on a running VM pending changes (e.g. a new memory size) were
  reverted and runtime state was written into the definition.

All of them now read VIR_DOMAIN_XML_INACTIVE | SECURE (PERSISTENT_XML).
The console setters take the first graphics device of that definition
instead of looking it up by the live type.

Disk resize no longer redefines the domain. A running VM's image files
grow through blockResize, since qemu-img cannot take the lock QEMU
holds; block volumes (e.g. LVM) are grown by the storage pool first and
QEMU is then told the new size.

Live tests reproduce the losses on a RHEL qemu-kvm host; unit tests
check the XML flags, the console setters and the resize paths in CI.

vrtManager/test_resize_disk.py

@@ -0,0 +1,45 @@
+import unittest
+from unittest.mock import MagicMock
+
+from django.conf import settings
+
+if not settings.configured:
+    settings.configure(MAC_OUI="52:54:10")
+
+from libvirt import VIR_DOMAIN_BLOCK_RESIZE_BYTES, VIR_STORAGE_VOL_BLOCK, VIR_STORAGE_VOL_FILE
+from vrtManager.instance import wvmInstance
+
+SIZE = 10 << 30
+
+
+def vm(active, vol_type):
+    inst = wvmInstance.__new__(wvmInstance)
+    inst.instance = MagicMock()
+    inst.instance.isActive.return_value = active
+    vol = MagicMock()
+    vol.info.return_value = [vol_type, 0, 0]
+    inst.get_volume_by_path = MagicMock(return_value=vol)
+    inst.resize_disk([{"path": "/dev/vg/disk", "size_new": SIZE}])
+    return inst, vol
+
+
+class ResizeDiskTestCase(unittest.TestCase):
+    def test_running_block_volume_grows_in_the_pool_then_in_qemu(self):
+        inst, vol = vm(active=True, vol_type=VIR_STORAGE_VOL_BLOCK)
+        vol.resize.assert_called_once_with(SIZE)
+        inst.instance.blockResize.assert_called_once_with("/dev/vg/disk", SIZE, VIR_DOMAIN_BLOCK_RESIZE_BYTES)
+
+    def test_running_image_file_grows_through_qemu_only(self):
+        # qemu-img cannot take the image lock QEMU holds
+        inst, vol = vm(active=True, vol_type=VIR_STORAGE_VOL_FILE)
+        vol.resize.assert_not_called()
+        inst.instance.blockResize.assert_called_once()
+
+    def test_stopped_vm_grows_the_volume(self):
+        inst, vol = vm(active=False, vol_type=VIR_STORAGE_VOL_FILE)
+        vol.resize.assert_called_once_with(SIZE)
+        inst.instance.blockResize.assert_not_called()
+
+
+if __name__ == "__main__":
+    unittest.main()